Fault Codes / Bosch / A21 (816)

BO

Bosch A21 (816)

Medium

Compress / Logamatic EMS plus — No communication with control unit heating circuit 1.

Bosch A21 (816): No communication with control unit heating circuit 1. This fault usually isn't an immediate stop, but should be checked soon.

Possible causes

Wrong address / wiring.

Check steps

Service level → P1: check address; RC20RF: battery.

Affected parts

Bedieneinheit
Batterie

Safety note

Low voltage — work carefully.

Source: Bosch Logamatic EMS plus Servicehandbuch 6720809288

Reviewed by Anıl Güzeldemir — in the refrigeration machine room since 2006, developer of Enthalio.

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